Having just gotten back from Pennsic, I'm going to touch on a topic that was deeply meaningful for a number of the grossly hot and humid days spent fencing there: Conditioning. Seriously, it's a thing. It's important, and it pays dividends in terms of your fighting.
I'd wager that most of us are fencing for one or both of two reasons: we like being competitive and kickass at swords, or we like doing sweet recreations of period manuals. Both of these have solid reasons for conditioning behind them, in their own ways. Let's take them one at a time.
Competitive combat. What we do out there with swords is an athletic activity, to be sure. If you think of yourself as a competitive athlete, why not treat yourself like one? Anaerobic exercise for individual bouts. Aerobic exercise for long tournaments. (Cardio. Always more cardio.) Strength for being able to move your weapon around quickly, smoothly, forcefully, and well. Flexibility for moving your body around and avoiding injury. These are all really important, and just going to practice isn't really going to work them all.
Look at any Olympic fencer, and think about how much they drill and practice - and on top of that, they still find the time to keep working conditioning exercises. If just raw practice and drills were enough to get the body built up, they sure wouldn't be doing any other conditioning - they are ridiculously efficient with their time and effort, and if there was a better way, they'd be doing it. For something closer to home, take a look at the armored combat people who are the serious contenders for Crown and ask them how much they work out when they decide to go fight. I bet most hit the gym pretty regularly.
Practice is absolutely necessary, but it doesn't work the whole body particularly well at all. (Compare your off-hand to your primary hand. Yeah. That's a thing.) Yet you need that whole body to fence really effectively. At least work some cardio in. Stretch regularly - every day, if you can. Consider strengthening exercises. It won't feel like much as you go, but based on the fact that I was still able to fight at the end of the melees this year, despite the crushing heat? Yeah, I blame having spent some real time actually exercising regularly. (If nothing else, we're all getting older, and exercise helps hold off the impact of entropy just a little bit longer. I'll do a whole lot to squeeze out one more year of fencing in my life.)
Let's move to recreation of period manuals. I could talk about how it's still athletic, and it still takes effort, and that's all true. But you're here for the manuals, so let's go look at two of them - specifically Fabris and di Grassi.
Fabris notes of his particular postures, "In order to properly learn how to keep your body low in this manner, you will need a fair amount of practice and hard work." Of his extended guards in general, he notes that they "can be fatiguing" and of particular ones "keeping the arm in this position for a long time is tiring." These are all good arguments for spending time growing stronger and more flexible.
Looking at di Grassi, though, is amazing. At the end of his manual, he has a section entitled, "On Training Alone In Order To Acquire Strength." He literally has a section telling the reader to go exercise. You can't get any better than that. One of the masters felt it was important enough to write down. So I guess if you're going to be working on recreating a manual, you should go work out. Giacomo di Grassi says so.
In all fairness, I get that most people aren't fencing as a lifestyle choice. It's a hobby, and people are going to make perfectly reasonable choices about how best to spend their time. However, I do think that if you're working hard on trying to get your fencing to the next level that spending some time to get the meat-car you live in tuned up to make it that much easier to properly perform the correct actions over and over again is very likely time well spent, and it'll end up showing in your fencing.
And that's what I wanted to get off my chest about conditioning. Next entry, we're back to Fabris!